Should I regrind my crankshaft?
Thread Starter
|
Drifting
Joined: Sep 2019
Posts: 34
Likes: 8
Should I regrind my crankshaft?
Hello guys,
I'm still working on my first BOSCH V8 4.0L engine rebuilt for a 2000 Discovery II. I'm done with the cleaning of the block.
I'm about to put the crankshaft back on and replace the main bearings, but before, I did take some measurements. There is no run-out on it and the diameter of the main bearing journals are inside the parameters 2.449 to 2.52 in as the overhaul manual states. My concern is with the conrod bearings journals. All of them measured in average 2.183 to 2.184 in.
On the manual the diameter for using standar bearings are 2.20 to 2.22 in and the under size 0.01 are 2.17 to 2.18 in, so I'm in the middle. Should I take the crankshaft to the machine shop and have them regrind to the undersize range or can I just use the standar bearings?
Thank you.
I'm still working on my first BOSCH V8 4.0L engine rebuilt for a 2000 Discovery II. I'm done with the cleaning of the block.
I'm about to put the crankshaft back on and replace the main bearings, but before, I did take some measurements. There is no run-out on it and the diameter of the main bearing journals are inside the parameters 2.449 to 2.52 in as the overhaul manual states. My concern is with the conrod bearings journals. All of them measured in average 2.183 to 2.184 in.
On the manual the diameter for using standar bearings are 2.20 to 2.22 in and the under size 0.01 are 2.17 to 2.18 in, so I'm in the middle. Should I take the crankshaft to the machine shop and have them regrind to the undersize range or can I just use the standar bearings?
Thank you.
Recovery Vehicle
Joined: Jun 2017
Posts: 1,238
Likes: 240
From: Alabama + Vegas + Texas
I ground the crank to the maximum .02 and then used the .02 oversized main and connecting rod bearings on the theory that:
#1: less rotating mass is better, and
#2: my machine shop would deliver a more perfect crank than what came new from LR.
...but, there's also something to be said for spending as little as possible on these vehicles, so I get the flip side argument.
#1: less rotating mass is better, and
#2: my machine shop would deliver a more perfect crank than what came new from LR.
...but, there's also something to be said for spending as little as possible on these vehicles, so I get the flip side argument.
Rock Crawling
Joined: Nov 2018
Posts: 303
Likes: 66
Hello guys,
I'm still working on my first BOSCH V8 4.0L engine rebuilt for a 2000 Discovery II. I'm done with the cleaning of the block.
I'm about to put the crankshaft back on and replace the main bearings, but before, I did take some measurements. There is no run-out on it and the diameter of the main bearing journals are inside the parameters 2.449 to 2.52 in as the overhaul manual states. My concern is with the conrod bearings journals. All of them measured in average 2.183 to 2.184 in.
On the manual the diameter for using standar bearings are 2.20 to 2.22 in and the under size 0.01 are 2.17 to 2.18 in, so I'm in the middle. Should I take the crankshaft to the machine shop and have them regrind to the undersize range or can I just use the standar bearings?
Thank you.
I'm still working on my first BOSCH V8 4.0L engine rebuilt for a 2000 Discovery II. I'm done with the cleaning of the block.
I'm about to put the crankshaft back on and replace the main bearings, but before, I did take some measurements. There is no run-out on it and the diameter of the main bearing journals are inside the parameters 2.449 to 2.52 in as the overhaul manual states. My concern is with the conrod bearings journals. All of them measured in average 2.183 to 2.184 in.
On the manual the diameter for using standar bearings are 2.20 to 2.22 in and the under size 0.01 are 2.17 to 2.18 in, so I'm in the middle. Should I take the crankshaft to the machine shop and have them regrind to the undersize range or can I just use the standar bearings?
Thank you.
Thread Starter
|
Drifting
Joined: Sep 2019
Posts: 34
Likes: 8
I ground the crank to the maximum .02 and then used the .02 oversized main and connecting rod bearings on the theory that:
#1: less rotating mass is better, and
#2: my machine shop would deliver a more perfect crank than what came new from LR.
...but, there's also something to be said for spending as little as possible on these vehicles, so I get the flip side argument.
#1: less rotating mass is better, and
#2: my machine shop would deliver a more perfect crank than what came new from LR.
...but, there's also something to be said for spending as little as possible on these vehicles, so I get the flip side argument.
Thread Starter
|
Drifting
Joined: Sep 2019
Posts: 34
Likes: 8
Hello guys, today I got my crankshaft back. I did a 0.010 cut on the main and conrod journals. Now I'm facing a huge struggle finding the right size bearings and it's driving me crazy.
I have been mainly purchasing my parts from E-bay and I just can't find any set that meets the undersize 0.010" or 0.25mm. Mostly are standar, 0.10 or 0.20, but they don't specify if oversize or undersize and neighter if that is mm or inches.
https://rover.ebay.com/rover/0/0/0?m...2F183435533281
https://rover.ebay.com/rover/0/0/0?m...2F182897987841
The only one that looks that may be the right size are these ones, but it is only the conroad bearings and haven't found anything for the main.
https://rover.ebay.com/rover/0/0/0?m...2F352521631103
I would really appreciate any help understanding what they mean with size .20 or .10 or if there is a place where I can buy a set that is not based in England and would take weeks to get the parts.
I have been mainly purchasing my parts from E-bay and I just can't find any set that meets the undersize 0.010" or 0.25mm. Mostly are standar, 0.10 or 0.20, but they don't specify if oversize or undersize and neighter if that is mm or inches.
https://rover.ebay.com/rover/0/0/0?m...2F183435533281
https://rover.ebay.com/rover/0/0/0?m...2F182897987841
The only one that looks that may be the right size are these ones, but it is only the conroad bearings and haven't found anything for the main.
https://rover.ebay.com/rover/0/0/0?m...2F352521631103
I would really appreciate any help understanding what they mean with size .20 or .10 or if there is a place where I can buy a set that is not based in England and would take weeks to get the parts.
Thread
Thread Starter
Forum
Replies
Last Post